Evaluating ten years of energy performance of HERS-rated homes in Alachua County,Florida

This paper evaluates the performance of 1,346 homes in Alachua County, Florida that were Home Energy Rating System (HERS)-rated between February 1998 and December 2009 for participation in various energy-efficiency programs for new residential construction. The primary analysis objective is to measure the energy-efficiency performance of these HERS-rated homes against conventionally built homes using metered energy consumption data for calendar years 2000–2010. A secondary objective is to assess performance of the four major builders of HERS-rated homes. In calendar year 2000, average energy savings for all HERS-rated homes was 18 %. However, over the following decade average savings degraded steadily, stabilizing around 7 % in the last 5 years of the analysis. We conclude that, while HERS-rated homes in the study area are performing better than similar conventionally built homes, the average HERS-rated home is not achieving the level of savings anticipated based on its HERS score and related energy-efficiency program participation. Differences in savings among builders of HERS-rated homes suggest that variations in program implementation and construction practices can yield significantly different energy performance results. Of the four builders tested, the least efficient averaged 3 % less energy consumed than conventionally built homes, while the most efficient averaged 21 % less. Overall, findings of this study indicate the need for re-examination of the HERS-rating process as a primary benchmark and for increased emphasis on direct measurement and verification of performance using historical energy consumption data.     

Investigation of the mechanical and thermal fatigue properties of hybrid sol–gel coatings applied to AA2024 substrates

This research article reports on the response of various hybrid sol–gel materials when applied as coatings to pre-treated bare AA2024 substrates, to mechanical indentation and cyclic thermal stimuli, in order to determine their usefulness in aeronautical applications. Three groups of hybrid sol–gel-coated samples were prepared using various organosilanes and transition metal oxides. The characterization of the materials revealed that the presence of the organic functionalities, especially the methacrylate group, has a noticeable effect on the mechanical response of the hybrid coatings, in particular their flexibility. The presence of methacrylate group in the cured material gives it ability to flex which influenced the thermal fatigue characteristics of the coatings which are able to withstand the cyclic temperature regimes of 82 ± 3 to ?37 ± 3°C over 25 2 h cycles. This capability to maintain substrate protection is reflected in the corrosion resistance of the coatings as measured using electrochemical impedance spectroscopy and accelerated exposure testing. This result is important, as it shows that hybrid sol–gel materials can be used in applications where protecting a metal or ally substrate is paramount, especially in thermally volatile environments.     

Investigation of Stainless Steel Corrosion in Ultrahigh-Purity Water and Steam Systems by Surface Analytical Techniques

Stainless steel pipes with different degrees of rouging and a Teflon^®-coated rupture disc with severe corrosion were thoroughly investigated by combining multiple surface analytical techniques. The surface roughness and iron oxide layer thickness increase with increasing rouge severity, and the chromium oxide layer coexists with the iron oxide layer in samples with various degrees of rouging. Unlike the rouging observed for stainless steel pipes, the fast degradation of the rupture disc was caused by a crevice corrosion environment created by perforations in the protective Teflon coating. This failure analysis clearly shows the highly corrosive nature of ultrapure water used in the manufacture of pharmaceutical products, and demonstrates some of the unexpected corrosion mechanisms that can be encountered in these environments.     

The House Mouse (Mus musculus L.) Exerts Strong Differential Grain Consumption Preferences among Hard Red and White Spring Wheat (Triticum aestivum L.) Varieties in a Single‐Elimination Tournament Design

Wheat (Triticum aestivum L.) plays a central role in the health and nutrition of humans. Yet, little is known about possible flavor differences among different varieties. We have developed a model system using the house mouse (Mus musculus L.) to determine feeding preferences as a prelude to extending results to human sensory analysis. Here, we examine the application of a single‐elimination tournament design to the analysis of consumption preferences of a set of hard red and hard white spring wheat varieties. A single‐elimination tournament design in this case pairs 2 wheat varieties and only 1 of the 2 is advanced to further tests. Preferred varieties were advanced until an overall “winner” was identified; conversely, less desirable varieties were advanced such that an overall “loser” was identified. Hollis and IDO702 were the winner and loser, respectively, for the hard red varieties, and Clear White 515 and WA8123 were the winner and loser, respectively, for the hard white varieties. When using the more powerful protocol of 14 mice and a 4?d trial, differences in mean daily consumption preferences of 2 varieties were separated at P‐values as small as 2 × 10^?8. The single‐elimination tournament design is an efficient means of identifying the most and least desirable varieties among a larger set of samples. One application for identifying the 2 extremes in preference within a group of varieties would be to use them as parents of a population to identify quantitative trait loci for preference.